仲景曰。太阳病。当恶寒发热。今自汗出。反不恶寒发热。关上
脉细数者。以医吐之过也。若得病一二日吐之。腹中饥。口不能食。
三四日吐之者。不喜糜粥。欲饮冷食。朝食暮吐。以医吐之所致也。
此为小逆。常氏云。可小半夏加橘皮汤、温中汤。
又曰。太阳病吐之者。但太阳病当恶寒。今反不恶寒。不欲近衣
者。此为吐之内烦也。常氏云。可金匮竹皮汤、竹叶石膏汤。雍曰。大
橘皮汤、四味橘皮汤皆可服。
又曰。少阴病。饮食入口则吐。心中温温欲吐。复不能吐。始得
之。手足寒。脉弦迟者。此胸中实。不可下也。当吐之。若膈上有寒
饮。干呕者。不可吐也。急温之。常氏云。可小半夏加橘皮汤、温中
汤。
又曰。诸四逆厥者。不可吐之。虚家亦然。庞氏曰。诸四逆脉微
弱细。或弦迟。虽中满闷。不可吐。宜橘皮汤、枳实散。
又曰。虚家当
吐而不敢吐者。宜以枳实散压气毒痰水。过日毒瓦斯入胃。乃可微下
之。
庞氏曰。不可吐而强之吐。气筑心则死矣。
仲景曰。大法春宜吐。
又曰。凡用吐汤。中病则止。不必尽剂也。
又曰。病如桂枝证。头不痛。项不强。寸脉微浮。胸中痞硬。气上
冲咽喉不得息者。此为胸有寒。当吐之。（一云。此以内有久痰。当吐
之。）常氏云。可瓜蒂散。
又曰。病胸上诸实。（一云作寒）胸中郁郁而痛。不能食。欲使人
按之。而反有涎唾。（一作浊唾）下利日十余行。其脉反迟。寸口脉微
滑。此可吐之。吐之。利则止。常氏云。可瓜蒂散。
又曰。宿食在上脘者。当吐之。常氏云。可瓜蒂散。
又曰。少阴病。饮食入口则吐。心中温温欲吐。复不能吐者。宜
吐之。常氏云。宜瓜蒂散。
又曰。病患手足厥冷。脉乍结。（一作紧）以客气（一作邪结）在
胸中。心下满而烦。欲食不能食者。病在胸中。当吐之。常氏云。可瓜
蒂散。
庞氏曰。胸膈痞闷。痰壅塞碍。脉得浮滑。并宜瓜蒂散吐之。产
后六七日内。下泻。诸药不效。得此脉者。吐之。泻立止。
千金伤寒论曰。得病无热。但狂言烦躁不安。精采言语不与人
相主当者。勿以火迫之。但以猪苓散一方寸匕服之。当逼与新水一
升。若二升。强饮之。令以物刺喉中吐之。病随吐愈。若不能吐者。勿
强与之水。水停则结心下也。当更以余药吐之。若此病辈。不将猪苓
散吐解之者。其死殆速。有水饮膈实者。皆难治。此三死一生也。雍
曰。心下停水。难治之疾。须早吐也。
病源曰。寒多热少。可吐者。此谓痰多也。治疟亦如之。
张仲景说：太阳病（太阳经受邪所致的病证），应当出现恶寒（怕冷）和发热。现在患者自汗出，反而不恶寒、不发热，且关部脉象细数，这是医生误用吐法造成的过失。如果患病一两天就使用吐法，患者会感到腹中饥饿，但嘴里却无法进食；患病三四天就使用吐法，患者不喜欢喝稀粥，想要喝冷饮，早晨吃下的食物晚上吐出，这也是医生误用吐法导致的后果。这属于轻微的逆证。常氏说，可以使用小半夏加橘皮汤、温中汤。
又说：太阳病使用吐法的，本来太阳病应当恶寒，现在反而不恶寒，甚至不想穿衣服，这是吐法导致体内产生烦热（内烦）。常氏说，可以使用金匮竹皮汤、竹叶石膏汤。郭雍说，大橘皮汤、四味橘皮汤都可以服用。
又说：少阴病（少阴经受邪所致的病证），饮食入口即吐，心中感觉泛泛欲吐却又吐不出来。刚发病时，手足发凉，脉象弦迟，这是胸中有实邪阻滞，不可使用下法，应当使用吐法。如果是膈上有寒饮，导致干呕的，则不可使用吐法，应当紧急温补阳气。常氏说，可以使用小半夏加橘皮汤、温中汤。
又说：凡是出现四肢厥逆（手脚冰冷）的情况，都不可使用吐法。身体虚弱的患者也是如此。庞氏说，各种四肢厥逆的患者，脉象微弱细或弦迟，即使伴有胸腹胀满闷塞的症状，也不可使用吐法，适宜使用橘皮汤、枳实散。
又说：身体虚弱的患者，本当使用吐法却不敢使用的，适宜用枳实散来压制气机、毒痰和水饮。过了一两天，毒邪瓦斯进入胃部后，才可以轻微地攻下。
张仲景说：治疗的大法，春季适宜使用吐法。
又说：凡是用吐药汤剂，达到治疗效果就要停止，不必服完全部剂量。
又说：病症表现像桂枝汤证（表虚中风证），但头不痛，项不强，寸脉微浮，胸中痞塞硬满，气向上冲至咽喉导致呼吸不畅的，这是胸中有寒邪，应当使用吐法。（另一种说法认为，这是因为体内有久积之痰，应当使用吐法。）常氏说，可以使用瓜蒂散。
又说：病位在胸部的各种实邪（另一种说法认为是寒邪），胸中郁郁不适而疼痛，不能进食，想要让人按压胸部，反而流出涎唾（一种说法为浊唾），腹泻一天十几次，脉象反而迟缓，寸口脉微滑，这种情况可以使用吐法。吐之后，腹泻就会停止。常氏说，可以使用瓜蒂散。
又说：宿食停滞在上脘的，应当使用吐法。常氏说，可以使用瓜蒂散。
又说：少阴病，饮食入口即吐，心中感觉泛泛欲吐却又吐不出来的，适宜使用吐法。常氏说，适宜使用瓜蒂散。
又说：病患手足厥冷，脉象突然结代（一种说法为紧脉），因为客气（一种说法为邪气结聚）停留在胸中，心下胀满而烦躁，想吃东西却吃不下，病位在胸中，应当使用吐法。常氏说，可以使用瓜蒂散。
庞氏说：胸膈痞闷，痰液壅塞阻碍，脉象浮滑的，都适宜使用瓜蒂散催吐。产后六七天内，出现腹泻，各种药物无效，出现这种脉象的，使用吐法，腹泻立即停止。
《千金伤寒论》说：患病没有发热，只是胡言乱语、烦躁不安，精神言语无法与人正常交流的，不要用火疗逼迫出汗，只需用猪苓散一方寸匕的量服用，同时强迫饮用新水一升或二升，然后用物体刺激喉咙使其呕吐，病随呕吐而愈。如果不能呕吐的，不要强行给水，水停留则会结聚在心下。应当再用其他药物催吐。像这类疾病，如果不通过猪苓散催吐来解除，死亡的速度几乎很快。有水饮停聚膈间导致实证的患者，都难以治疗，这是三死一生的情况。郭雍说：心下停水，是难治的疾病，必须尽早使用吐法。
Zhang Zhongjing said: In Taiyang disease (a syndrome caused by pathogenic factors affecting the Taiyang channel), aversion to cold and fever should be present. Now, if the patient sweats spontaneously but conversely lacks aversion to cold and fever, and the pulse at the Guan position is fine and rapid, this is an error caused by the physician's use of emesis. If emesis is induced one or two days after contracting the disease, the patient will feel hungry in the abdomen but unable to eat; if emesis is induced three or four days after contracting the disease, the patient will dislike congee and desire cold food, vomiting what was eaten in the morning by evening. This is also caused by the physician's improper use of emesis. This constitutes a minor adverse reaction. Chang Shi stated that Xiao Banxia Jia Ju Pi Tang (Minor Pinellia with Tangerine Peel Decoction) or Wen Zhong Tang (Warm the Middle Decoction) could be used.
He further said: When emesis is used for Taiyang disease, since Taiyang disease typically involves aversion to cold, the current absence of aversion to cold and the desire not to wear clothes indicate internal heat agitation (Nei Fan) caused by emesis. Chang Shi stated that Jin Gui Zhu Pi Tang (Golden Cabinet Bamboo Flake Decoction) or Zhu Ye Shi Gao Tang (Bamboo Leaf and Gypsum Decoction) could be used. Guo Yong stated that Da Ju Pi Tang (Major Tangerine Peel Decoction) and Si Wei Ju Pi Tang (Four-Ingredient Tangerine Peel Decoction) are both acceptable.
He further said: In Shaoyin disease (a syndrome caused by pathogenic factors affecting the Shaoyin channel), food and drink are vomited immediately upon entering the mouth, and there is a sensation of nausea in the heart region without the ability to actually vomit. At the onset, the hands and feet are cold, and the pulse is wiry and slow. This indicates excess in the chest; purgation is contraindicated, and emesis should be employed. However, if there is cold-fluid retention above the diaphragm causing dry heaving, emesis is contraindicated, and urgent warming of Yang Qi is required. Chang Shi stated that Xiao Banxia Jia Ju Pi Tang or Wen Zhong Tang could be used.
He further said: In all cases of Si Ni Jue (Reversal Cold of the Four Extremities), emesis is contraindicated. The same applies to patients with deficiency constitutions. Pang Shi stated that in various cases of Si Ni, where the pulse is weak, minute, fine, wiry, or slow, even if accompanied by fullness and oppression in the middle jiao, emesis is contraindicated. Ju Pi Tang (Tangerine Peel Decoction) and Zhi Shi San (Immature Bitter Orange Powder) are appropriate.
He further said: For patients with deficiency constitutions who require emesis but dare not undergo it, Zhi Shi San should be used to suppress qi stagnation, toxic phlegm, and water retention. After a day or two, once the toxic pathogens have entered the stomach, mild purgation may then be performed.
Pang Shi stated: Forcing emesis when it is contraindicated can cause qi to strike the heart, leading to death.
Zhang Zhongjing said: The general principle is that emesis is suitable in spring.
He further said: Whenever emetic decoctions are used, discontinue administration as soon as the therapeutic effect is achieved; it is not necessary to consume the entire dose.
He further said: If the symptoms resemble those of the Guizhi Tang pattern (Exterior Deficiency Wind Strike Pattern), but there is no headache or stiffness of the neck, and the Cun position of the pulse is slightly floating, with oppression and hardness in the chest, and qi rushing up to the throat causing difficulty in breathing, this indicates cold pathogens in the chest, and emesis should be employed. (Another version states that this is due to long-standing phlegm in the interior, requiring emesis.) Chang Shi stated that Gua Di San (Melon Seed Powder) could be used.
He further said: Regarding various excess conditions in the upper chest (another version reads "cold"), with a feeling of depression and pain in the chest, inability to eat, a desire for someone to press on the area, yet producing saliva (one version reads turbid sputum), and diarrhea occurring more than ten times a day, while the pulse is surprisingly slow and the Cun Kou position is minute and slippery, emesis is indicated. After emesis, the diarrhea will cease. Chang Shi stated that Gua Di San could be used.
He further said: When retained food stagnates in the Upper Wan (upper part of the stomach), emesis should be employed. Chang Shi stated that Gua Di San could be used.
He further said: In Shaoyin disease, where food and drink are vomited immediately upon entry, and there is a sensation of nausea in the heart region without the ability to vomit, emesis is appropriate. Chang Shi stated that Gua Di San is appropriate.
He further said: When patients present with cold extremities and a pulse that suddenly becomes knotted (one version reads tight), because external pathogens (one version reads pathogenic knotting) are lodged in the chest, causing fullness below the heart and irritability, and a desire to eat but inability to do so, the disease is located in the chest, and emesis should be employed. Chang Shi stated that Gua Di San could be used.
Pang Shi stated: For oppression and stuffiness in the chest and diaphragm, obstructed by excessive phlegm, with a floating and slippery pulse, Gua Di San is suitable for inducing emesis. In cases of diarrhea occurring six to seven days postpartum, unresponsive to various medications, if this pulse pattern is observed, emesis will stop the diarrhea immediately.
The Shanghan Lun from Qian Jin Fang stated: When a patient has no fever but exhibits delirium, restlessness, and incoherent speech lacking normal interaction, do not force sweating using fire therapy. Instead, administer one square-cun measure of Zhu Ling San (Polyporus Powder), and forcibly make the patient drink one or two sheng of fresh water, then stimulate the throat to induce vomiting. The disease will resolve with the vomitus. If the patient cannot vomit, do not force water intake, as stagnant water will bind in the epigastrium. Use other emetic agents instead. For such diseases, if not resolved through emesis with Zhu Ling San, death will likely occur rapidly. Patients with water-fluid retention and diaphragmatic excess are difficult to treat; this represents a scenario with three chances of death and one of survival. Guo Yong stated: Water retention in the epigastrium is a difficult-to-treat condition requiring early emesis.
The Bing Yuan Fang Lue stated: Malaria characterized by more cold than heat may be treated with emesis; this refers to cases with excessive phlegm. The treatment for malaria follows this principle.